Dental-plate swage.



' PATENTED JUNE 18, 1907. G. B. PREBBORN. I

DENTAL PLATE SWAGE. APPLIOATION FILED I'EB.12. 1906.

i As I I @uvmutoz A u v Z GRANT E. FREEBORN, OF BELFAST, NEW YORK.

DENTAL-PLATE SWAGE.

Specification of Letters Patent.

Patented June 18, 1907.

Application filed February 12, 1906. $orial No. 300,789.

1'0 all whom, it may concern:

Be it known that I, GRANT E. FREEBORN, of the town of Belfast, in the county of Allegheny and State of New York, have invented certain new and useful Improvements in Dental-Plate Swages,'(for which I have obtained a patent in Canada, No. 96,499, bearing date the 12th day of December, 1905;) and I do hereby declare that the following, taken in connection with the accompanying drawings, is a full, clear, and exact description of the same.

The invention relates to appliances for shaping sheet metal dental plates; and the objects of my improvements are, first, to provide a simple form of swage which is divided about on the plate line of the die and can consequently be opened for inspection at any stage ofthe operation without any detriment to the plate, and particularly the undercuts of the plate are accessible for malleting; and second, to provide means for preventing leakage under the heavy pressure necessitated in swaging sheet metal over a die.

In the drawings, Figure 1 is a sectional view of the swage at line XX in Fig. 2, and

showing a plate in the process of swaging, one of the clamps being released and the other compressing the lugs together to form a binding joint. Fig. 2, is a plan view of the swage showing the retaining ring and die in dotted lines. Fig. 3, is a side elevation of one of the end clamps. Fig. 4, is a sectional view of a modification of theswage with aninner ring.

Similar numerals refer to corresponding parts in the several views.

The swage is divided on a line with the plate line on the die. The two parts of the swage are indicated by the numerals 10 and 11. Vertically opposite lugs 16 and 17 are provided on parts 10 and 11 to receive the clamps 18, which clamps are preferably operated by screws 19. The lower ends 20 of screws 19 bear on the upper lugs 16 in compressing the parts together. Clamps 18 are also set close to the main body of parts 10 and 11, as shown at 21 in Fig. 2, so as to hold the parts firmly in place and prevent their springing under heavy blows. The upper part 10 sets on the lower part 11 with a bevel joint 12. The joint between the two parts is formed with a slight opening toward the outer side. To form this the upper part 10 is preferably given an upward bevel extending from the inner edge outward andthe face hammer.

divided swage has its upper opening 26 made ing swage the plate.

of the lower part 11 is made flat. should be slight, about one sixty fourth of an inch between the outer ends of the lugs 16 and 17 being sufficient leverage to obtain a binding joint and allow the lugs to be pressed firmly together by clamps 18, as shown at 12 in Fig. 1, so that they are as one against breaking strain. A larger amount of bevel would not allow the two lugs to thus come together and they are then liable to break under the enormous pressure attained in swaging. The inner edge of the bevel cuts on to the lower part 11 with a contacting joint 12 which with the binding of the joint This bevel I is sufficient to prevent all leakage in swaging the usual gage of dental plates.

For extra heavy plates I prefer the insertion of an inner ring 14, across joint 12 as shown in Fig. 4, which ring is made to fit tightly within the top part 10, so that in opening the swage it remains in place. A seat 13 is made in lower part 11 for the lower edge of ring 14, which seat has a slight vent extending toward the joint 12 in order that the ring 14'may be easily removed in opening the mold, and so that the ring will also immediately seek its place in putting the two together. The upper edge 15 has a close joint. It is apparent that the ring 14 will rovide joints 13 and 15 in addition to the wife joint 12 and in front of said joint and between the die and the joint, thus absolutelypreventing all liability to leakage, yet allowing of the easy opening of the swage.

The central portion of part 10 is extended upward in a cylindrical tube 22. A plunger 23 is provided to fit the tubular opening 25 in tubular ortion 22, and has an elongated head 24 suitable for striking with a heavy The interior of the horizontally in conical form to allow equal pressure to all surfaces. Lower part 11 has a cup-shaped opening 27 therein. Opening 27 is filled with a stiff resinous compound which melts at low temperature; the modeling compound used by all dentists supplying this purpose perfectly. The upper conical opening 26 is filled with a wax compound, to form a counter-die and is preferably composed of sixteen parts paraffin to one part of Venice turpentine. This gives a tough formwax which has sufiicient resistance to The same wax is used over and over in swaging plates. The opening in the wax formed by the die and plate remains about the same so as to uickly conform to the change in shape of the different plates. Ring 14 is held in upper part by the wax and its close fit. Die 28 is made of metal which melts at low temperature preferably at about 170 Fahrenheit.

A shoulder 23 is made in plunger 23 about three fourths of an inch below head 24 and the body of the plunger rod is made smaller between head 24 and shoulder 23; which arrangement prevents all binding of the plunger 23 in opening 25, and also marks the amount of compression and depression of the wax, which depression under the ordinary blow of the hammer is about'one half inch in the tubular opening 25. When the shoulder 23 sinks below the top of tube 22 the under side of the shoulder on head 24 is liable to strike on tube 22 on account of the resiliency of the wax thus preventing the swaging of the plate, injuring the machine, and is not recognizable by the operator, since the return of the plunger is practically instantaneous with the blow of the hammer. Therefore whenever shoulder 23 stands normally below the top of tube 22, the plunger should be removed and more wax added. Projections 31 are provided on lugs 16 on the side opposite the front of die 28 so that the operator knows the exact position of his die.

The operation of making a dental plate is as follows The impression of the mouth is taken with plaster of paris or modeling compound and this impression may be immediatelyfilled with the melted low-temp erature metal for the die without waiting for the cast to dry, since the metal melts at a temperature below the boiling point and hence moisture will not create air bubbles. Accordingly the metal may be run into the wet plaster of paris impression, or,.it may be used in the same manner in the modeling compound impression without softening the wax. It is then placed in water, instantly setting the metal hard. The die 28 is now ready to be placed in the modeling oompound in opening 27; the compound having first been softened by setting in hot water or over a flame for a few moments. This allows the die 28 to sink into the compound to the desired depth, at which point the compound may be instantly set hard by running cold water over it. This holds the die 28 firmly .in place. Die 28 is placed with its front toward the projections 31 so that the operator knows the exact position of his die and can open the parts of the swage from the rear side of the die and thus not break or bend the under-cut of the plate. the die 28 being slightly above the level of the lower part 11, the under-cut of the die is accessible for malleting. The thin sheet metal 29 for the plate is placed over the die and a piece of sheet rubber 30 such as is used by dentists for rubber dam work, is placed over the plate 29, which rubber extends out The gage said lugs and form It is apparent that through joint 12 and forms a packing to seal said oint against leakage as well as separate the plate from the wax within the swage. upper portion 10 is now forced down upon the die and plate by means of clamps 18 which give great leverage power in holding the parts together and preventing leakage. Plunger 24 is then struck a number of blows with the hammer, three blows being usually sufficient to complete the plate, thereby forcing the wax in the upper part about all parts of the die and forcing the sheet metal of the plate to conform to the least depression in the die. It is apparent that great pressure willbe given by such blows to the confined die and plate, estimated at about three thousand five hundred to four thousand pounds to the square inch; sufficiently powerful to cause a plate of eighteen gage gold or aluminium bronze to copy the die. It is obvious that under such pressure any liability to leakage is a great detriment, and that this is overcome by the binding joint 12 and its rubber packing 30.

A metal plate swaged by this method, on being removed from the swage is as bright and smooth as when put in, thereby preventing the necessity of polishing away of at least two gages in thickness of the gold or other material used.

I claim as new:

1. A dental plate swage composed of upperand lower parts, said parts having a plane of separation therebetween on the line of the plate, a binding joint uniting said parts which allows of horizontal movement in any direction in separating the same, a forming compound within said parts, and means for compressing said compound on the plate and die.

2. In a dental plate swage, a hollow base comprising upper and lower portions, lugs on said portions, an outwardly opening angle in the joint between said parts, clamps to ena binding joint by closing said angle between said parts, a tubular opening in said upper portion, a plunger operable in said opening, a suitable die and compound for counter-die within said base, and a sheet of rubber between said die and counter-die and binding joint.

3. A dental plate swage composed of upper and lower parts, a flat joint between said parts slightly opening toward the exterior, a clamping means to close said slight opening and form a binding joint between the parts, a forming compound within said swage, a tubular opening in said upper part, a plunger operable in said opening to compress said compound onto the plate, said plunger having a reduced portion next to the head, substantially as and for the purpose specified.

4. In a dentalplate swage,ahollowbase comprising a cup-shaped lower portion having a flat upper face around said cup, a hollow up- I I 0 sheet of flexible material between said die and per portion having its lower edge beveled outwardly at an upward angle to form a binding joint with said lower portion, lugs on said In testimony whereof we have signed our portions, clamps for said lugs to form said names to this specification in the presence of extending out through said binding joint to 5 binding joint, a tubular opening in said upper two subscribing witnesses.

form apacking.

portion a plun er operable in said opemng having a shoulder to gage the amount of com- GRANT FREEBORN' pression, a suitable die and compound for Witnesses: GEo. L. HUssoNG,

LEONARD L. ROTH.

counter-die within said hollow base, and a 

